Liroharp werdermann



(No Model.)

B. WERDERMANN Electric Lamp. No. 240,795. Patented April 26,188L

UNITED STATES PATENT OFFICEQ RICHARD YVERDERMANN. OF LONDON, llhTiLAlYl).

ELECTRIC LAMP.

'PECIPICATION forming part of Letters Patent No. 240,795, dated April26, 1881.

Application filed June 30, 192 0 (No inedel.)

To all 10710111, it 7)L(l[/ concern:

Be it known that I, RICHARD \VE'RDER- MANN. of London. England, civilengineer, have invented new and useful Improvements in Electric Lamps,(for which I have obtained Letters Patent in (lreat Britain, No. 2,477,

bearing dateJune 21, 1878, and No. 2,301, hearing date June 10, 1879,)of which the following is a specification. I

My said invention relates to improvements in electric lightingapparatus, and comprises various novel devices and arrangements of theparts of such apparatus as hereinafter set forth.

In order that my said invention and the principle upon which it isfounded, as well as the manner in which I carry the same. into effect,may be fully understood, I desire to make the following preliminaryrcmarks that is to say, when'in an electric lamp or lighting apparatuselectrodes each havingthe same sectional 'area are used, the changes atthe points between which the voltaio arc is produced take place in amanner which is well known to electricians, namely, a crater or hollowis formed in the positive electrode, which emits the light, this craterbeing heated by the electric current to whiteness and the surroundingpart to redness, while the negative electrode, which, under theinfluence of the current, assumes the form of a'eonc, is only heated toredness and emits scarcely any light.

I have discovered that an increase in the sectional area of the positiveelectrode diminishes the light emitted by this electrode, and it thisdifference bet ween the two electrodes is very great the positiveelectrode ceases entirely to emit light, whereas the heating ef fectupon the negative electrode in connection therewith is increased, andlight is emitted by the same; and, furthermore, by increasing thesectional area of the negative electrode the heating effect upon thesame is decreased proportionally to the increase of its area, until,

- the area having been increased sufficiently,

the heat disappears altogether, and conse' quently no consumption orwearing away of the said electrode occurs. The light emitted by thepositive electrode in connection therewith, on the contrary, isincreased in proportion to the difference between the sectional areas ofthe two electrodes, and instead of a Patented in England Tum-2i, WW, andJnnelt), ISTEI.

crater being formed in the positive electrode thelattcr assumes the formof a cone, as former] y was the case with the negative electrode. Incarrying my said invention into practice I propose to adopt thisniani'icr of arranging the electrodes to produce an absolutely steadyand noiseless electric light, and for this purpose I provide anelectrode of circular, square, prismatic, or other convenient form intransverse section, and which I fit in a holder connected with one poleof either a gal vanic battery, a magneto-electric machine, or any othersource of electricity, or of an induction-coil or condenser, 01' otherintermediary apparatus. In contact with the surface of this electrode,which surface may be either plane or curved, I place another electrodeof suitable shape, but of much smaller sectional area, and which is keptpreferably in a vertical or inclined position, or in a horizontal or anyother desired position, by a holder, in which it is allowed to slideupward, downward, or otherwise, being maintained in the same in a steadycondition, either by means of friction rollers, brushes, springs, orhollow cylinders 01 tubes in two or more parts, or by other convenientmeans. This electrode during the emission of the light is kept inconstant contact with the aforesaid large electrode either by weights,springs, or the pressure of mercury or other liquid, or by othersuitable means, so that while it is slowly consumed the electric circuitis never broken, and a steady, brilliant, and noiseless light is emittedby the heating to incandescence of the smaller electrode at its point ofcontact with the larger one, where an infinitesimally small voltaic arcis produced, to which the incandescence ofthc smaller electrode isduethat is to say, the resistance at the point of imperfect contactcauses the formation of an infinitesimally small electric or voltaic areand the incandescence of the electrode. Therefore, it will be seen thatin my invention the existence of the voltaic arc is necessary for theemission of the light, as in various other arrangements for theproduction of electric light, this feature forming a very importantdistinction between such lights and those in which thelightis producedsolely by the incandescent-e of the portion of an electrode between twopoints of contact.

It is advantageous to make the connection ot'the electric current, inordcrto avoid the extension of the intense heating too near to thecontact where the current enters the said electrode. For the same reasonthe pressure between thctwo electrodes must be regulated in accordancewith the intensity of the electric current, becauseit' the pressureistoo greatno voltaic are would be produced, but. incandescence of thewhole length of the carbon be tween the points of contact (which Ipartieuform of the said devices.

larly desire to avoid) will occur, and there will be no effect ofelectric repulsion.

In the method by which I produce my light. no incon\-'enience resultsfrom the deposit of any impurities upon the surfaces of the carbons;therefore, I am not compelled to resort to any cont-rivances for givingto the large carbon any movement or adjustment looking to the preventionof such deposit.

The proportion between the sectional area of the two electrodes I prefershould not be less than about one to four, which proportion Lil is, inmost cases, sufficient to prevent consumption or wearing away of thelarger electrode, which is of the highest importance; but I prefer amuch greater difference between the sectional areas of the electrodes,and generally adopt the proportion of about'one to sixtyi'our.

The said invention consists in improved means for constantly keeping thetwo electrodes .in the proper relative position with regard to eachother, whatever may be the irregularity in the consumption of thevertical electrode or carbon rod during the development of the light.

It also consists in means whereby the carbons'or electrodes in any lampin a circuit will be automatically cut out of, or detached from, thesaid circuit whenever the carbon-rod oi' the said lamp is entirely ornearly consumed, so that when any one or more of the lamps in thecircuit is in this condition the other-lamps will not be in any wayailected thereby.

The said invent ion also consists in improved means whereby any excessor deficiency in the rate of movement of the smaller electrode or carbonpencil will cause the larger electrode or carbon disk to move and adjustdevices which immediately counteract such excess or deficiency. By thesemeans I am enabled to insure the uniformity of the light, which dependsin a great measure upon the maintenance of an exact proportion betweenthe rate of combustion of the smaller electrode and the rule ol'itsmovement toward the larger electrode.

The'apparatus for advantageously carrying my said invent ion into practice is clearly shown in the accompanying drawings; but I wish itunderstood that 1' do not limit myself to the details of theconstruction aml arrangements shown in these drawings, as manymodifications of the same are possible and may he required to adapt thesaid apparatus to the circumstances or conditions of each particular 5case.

l l l In the drawings, Figure 1V is a view of a lamp constructedaccording to my invention, the standard being shown in vertical section.

Fig. 2 is a side elevation of a portion ofa lamp,

representingone form of my improved devices for maintaining the twoelectrodes in their proper relative position, and for cutting out thecarbons or electrodcsin a circuit whenthe carbon rod is entirely ornearly consumed, amt Figs. 3 and 4 are similar views of a modified Fig.5 is a side elevation, partly in section, of another modified form ofthe said devices, and Fig. 6 is a plan of portions of the same. Fig. 7is a vertical section of a still further n'iodilied form of the saiddevices.

Like letters indicate corresponding parts throughout the drawings.

Referring to Fig. 4, illustrating one form of my improved lamporlightgiving device, a is a standard or pillar,i.vhich may beconstructed of metal or other suitable material, and which supports theelect rodcs and the mechanism connected therewith.

b is the fix ed electrode, which is considerably'larger in its sectionalarea than the other electrode. it may be formed entirely of can bon orwith a core or central part of carbon, surrounded by a ring or outerportion of other suitable material. b is the clamp or holder in whichthis electrode 1) is secured. I have hereinabove stated that in myapparatus no movement of this large elect-rode is required for thepurpose of preventing the deposit of cinder thereon, and it will be seenthat no meansl'or producing such movement are shown; but the clamp bpermits the ready insertion, removal, and adjustment of the saidelectrode. The clamp is provided with an arm, I)", which is pivoted to apiece, 1/, fitted to slide on the fixed vertical bar, and the said armI) is connected wit-h the devices for controlling the movement of thelower carbon, as will be presently described,with reference to figuresshowing the parts enlarged.

c is the movable electrode or carbon-rod, which is fitted to slidethrough the guides hereinafter described, and is thereby kept in contactwith the disk b,wit-h exactly the required pressure, by the followingdevices.

(I is a piece fixed within the standard or pillar a, and to which aresecured the small pulleys (1. Over these pulleys are passed chains,cords, or hands d", which are secured at one end to the rod 0, and haveattached to their ol her ends the \\'eiglitj,wmcli is fitted-to slideupon the tube 0,which incloses the said rod 0. The latter is fitted toslide through the fixed piece (I and in the said tube, which is securedat its lower end to the pieceg, fixed in the pillar u. The piece d hasin it a cavity or recess for the reception of the lower end of the lube/z,whose upper end is fitted within the tube '1', fixed at the top ofthe standard a. The elec trode or carbon rod 0 is inclosed within thetube 7:, and, by sliding upward in the same, is kept in continualcontact with the disk 'I). The sliding weight is accurately adjusted topreponderate over the weight to-bc raised just sufliciently to keep thepoint of the electrode c in continual contact with the electrode or diskI) with the slightest possible pressure. The tube i forms the aforesaidguides. This tube is secured by its lower end in the pillar or standard,as above specified, and its upper portion above the line i is dividedinto two parts or halves, fitted together and kept in the properposit-ion by pins 1" or by other suitable means.

As before stated, I provide the clamp b with an arm, Zr, which ispivoted to a piece, b reference being now made to Fig. 2, fitted toslide on the said fixed vertical bar. The said arm is arranged in such amanner that it can 1 move upon this pivot as its center, and thereforethe larger or upper electrode 1), with the said arm I)", is capable ofadjustment toward and away from the lower electrode or carbon pencil, c.The said arm 0- extends beyond its pivot on the vertical rod a, and isscrewthreadcd upon a portion ofitslength and provided with a nut, b*, onthis screwed portion. the said nut being sutliciently heavy tocounterbalance the elect rode or disk I). The said nut isto besoadjusted thatthe weight of the electrode will slightly prcponderate overthat of the nut, in order that the electrode may descend when not incontact with the point of the smaller or vertical electrode or carbonrod 0, and as the latter is consumed the larger electrode assists by itsgravity in maintaining its proper connection with the smaller. electrodeor carbon pencil c. The latter is fitted to slide through guides i, asabove described, thctwo portions 1' i of which are fitted together bypivoting one to the other at i, or otherwise so connecting them that thepart i will be capable of adjustment. In commencing to work, theseguides are adjusted as nearly as practicable to exert the requiredpressure upon the carbon rod, to insure its moving upward at the properrate of speed by the action of the springs, weights, or other means usedfor this purpose; but this upward movement cannot be advantageouslymaintained at one uniform rate, because of the va riations which occurin the rate of combustion of the carbon. 1 therefore provide for varyingthis rate of movement inproportion to the variations in the rate ofcombustion by in creasing or decreasing the lateral pressure on the saidcarbon rod, to prevent its traveling too slowly or too rapidly. Thisvariation of pressure is obtained automatically and with greatexactitudc, according to the require ments of the lamp, under allcircumstances, by the following devicesthat is to say, a flat spring-orspring-bar, j, is placed near the said preferably provided with amilledhead to fa-' cilitate its manipulation, so that the point of thescrew which extends through the spring to the surface of the guide imayset or adjusted, as required. Thcsaid spring orspringbar is attached atits lower end to the short to a lug or car on the standard or pillar u.The other arm, j", of 1 his lever is bifurcated at its extremity, tofita doubly collared or flanged nut, j, on avertical rod, j, connectedat its upper end to the aforesaid arm I), which can I ries the largerelectrode 7). The aforesaid doubly flanged screw-nut has it flanges orcollars milled, to facilitateitsmanipulation. This nut provides for anyrequired adjustment of the two-armed lever, and consequently ot' thevertical spring attached thereto.

From the above description it will be seen that the vertical rod j"being connected to the arm Z1", carrying the larger electrode. moveswith it, and that any motion imparted to this red will be communicatedthrough the two armed lever j j" to the springj and the screw j. Shouldthe carbon rod orpcncil c be rising too rapidly by reason ofinsuiiicieni pressure on the guides, the large or upper electrode 1)will be thereby pushed upward, consequently the vertical rodj will alsorise, carrying with itthe bifurcated arm j of the two-armed lever, thepoint of the screw j in the upperend of the spring being then pressedagainst the guide-piece i, and the pressure or friction of the latter onthe carbon rod c being increased, the upward movement of the said carbonrod will thereby be immediately checked or retarded, so that it is nolonger loo rapid forthe rate of combustion of the carbon. and the uppercarbon 72 will then descend to its normal position. As it descends thevertical rod also descends, and the pressure of the screw) on theguidepiecc i is relaxed, so that the speed ot'thc carbon rod maybe againaccel erated, if not quick enough. Thus the speed of the carbon rod iscontinuously and automatically regulated. and there will be no variationor irregularity of the light by reason of variations in the rate ofcombustion, or excess l or diminution of weight of the carbon.

It will be obvious that the variations in the movement of the rod 0 andot' the disk (I, and parts connected therewith, will be very slight. as,in comn'icneing to move, the said disk immediately imparts acompensating or counteracting movement to the checking devices; and l asthe said regulatingor checking devices are exceedingly delicate orsensitive, they will be subject during the development of the light to asuccession ofminute and imperceptible oscillations, which will notpermit the slightest perguides, and has in its upper part a screw, 9'',

i arm, 3*, ol' atwoarmed lever, which is pivoted I of this rodj thatwhen this descent occurs its lower end will come into contact with ascrew,

j, in an arm extending from the standard or pillar u. The lower portionof the rod j" is insulated from the upper portion by theintroduction ofany suitable insulating material at f the electriccurrcnt will thereforebe providcd with a short circuit-that is to say, it

will not travel from the wire or conductor 1 through the carbons, butthrough the bifurcated arm j of the two armed lever to the vertical rodj, thence through the screwy": with which the end of this rod is incontact, and thence to the line-wirc out of the lamp. The carbons inthis particular lamp will thus automatically be cut out of or detachedfrom the main circuit, and the otherlamps in the circuit will not beeffected.

In the modified form of the devices for ob taining the above-namedresults, as shown in Fig. 3, the two electrodes, b c, are arranged asabove described; but instead of using a regulating device consisting ofthe vertical rod and spring or spring-bar and two-armed lever, I attachto the pivoted arm b carrying the larger or upper electrode, 1), aspring, k. so formed that its lower end extends to,*or nearly to, thesurface of the guide '1 and at this part of the latter I provide a pieceof some insulating material, as shown at z. The lower end of this springk therefore serves the same purpose as the sercwj in the end of thespring j, hereinbefore described. If the carbon rod or electrode 0rises-too rapidly and raises the upper or larger electrode 1), thespring I." also rises, and its lower end presses against the guide andretards the movement of thecarbon rod 0, and the falling of the upperelectrode relaxes the pressure, as and with the effect above described.This bent spring also serves to short circuit vthe current as fol-'lows-that is to say, an arm, i", is attached to the lower part of theguides i, and extends upward to such a position that when the carbon orelectrode 0 is nearly consumed, and the upper carbon or disk, b, hasdescended, the lower end of the said spring k comes in contact with thearm or piece i", thereby forming a short circuit through the arm 1?,spring 1.", arm b, and pillar a.

In the modification of the said apparatus illustrated in Fig. 4, thecarbon disk or electrode b is carried by the arm b", which is pivoted atb to the vertical rod or bracket (4. The latter is formed of ebonite orother suitable insulating material, or if made of metal, is insulated inany convenient manner. At b this arm b has jointed to it a rod or link,b whose lower end is jointed to the long arm tached at its fulcrum b tothe adjustable part z" of the guide, so that this part of the guidev ismovable with the said lever. Consequently, when the disk b is raised byreason of the too rapid upward movement of the carbon rod 0, andthereby, through the link b", depresses the arm I) of the said lever,the upper extremity of the part '5 of the guide is-forced inward, andthus the lateral pressure upon the carbon rod P will be increased. Thenthe upward movement of the carbon rod 1 will be retarded until the diskb descends and relaxes the lateral pressure of the guide on the rod 0.The compensating action thus obtained will, as above described, preventany perceptible variation or fluctuation of the light, as in theapparatus above described \Vhen the carbon rod 0 is nearly consumed, thelamp is shortcireuitcd as follows: The descent of the disk b and its armb'-' causes the rod If and arm b ot' the two-armed lever to rise.Consequently, the short arm b of the said lever has its adjustable screwor stud I) brought int-o contact with the plateor piece b, with whichthe conducting-wire 2 is connected. The current then passes from thepoint b through the arm b of the said lever, and through the stud b andpiece b", to the wire 2.

According to another modification of the said apparatus, illustrated inFigs. 5 and 6, the clamp or ring b, which carries the carbon disk b, issupported ecccntrically on pivots or pintles b fitted in a fixedhorizontal arm extending from the rod or bar a. The eccentricity of thecarbon disk is such that its weight preponderates on the side with whichit is in contact with the carbon rod 0. The spring I. in this case isfixed on the ring or clamp b of the disk b, and bears against a piece ofinsu lating material on the guide 1', as in the apparatus shown in Fig.3. The eli'ert of the raising and lowering of the disk band the resulting compensating action of the regulating devices will be the same inthis form of my invention as in those above described, and theshort-cireuiting devices may be arranged as in Fig. 3, or in any othersuitable manner.

In Fig. 7 the lateral pressure on the carbon rod c, for the purposeabove specified, is controlled or regulated by means of two rollers, cc, mounted on a rod or bar, 0-. which is pivoted or i'ulcrumcd at c",and extends through aspace or opening in'the lower partof the guides.One end ot'thisbarisconuected to the lower end'of a vertical rod, 0,whose upper end is attached to the arm b", which is connected with theupper or larger carbon b. To the other end of the said roller-bar a" aspiral spring is attached, the latter being con nectcd to ashort rodprovided with a nut, by which it may be adjusted vertically. The tensionof the spiral spring is adjusted, by any suitable means, to regulate thepressure of the rollers on the carbon rod. The rising and fall ing ofthe upper electrode or carbon ball b will have the same compensatingefi'ect as in the other forms of my improved apparatus above described.

My improved apparatus may be readily and conveniently adapted to theexisting streetlamp posts or pillars.

As will be seen from the foregoing explanation, the electric light of myimproved apparatus is not due to what is termed incandescence, but tothe production of a voltaic are, which, though infinitesimally small,exists and is due to the infinitesimally small distancc which separatesthe electrodes, and to the phenomcnonot the repulsion or rcpulsionsexerted by the adjacent or contiguous elements of the voltaic orelectric current. The best effect of the light can only be obtained byobservance of the proportions between the areas of the electrodes, thedistance between the points of contaet,thc p ressu re,and the strengthor intensity of the current,as above explained. These proportions cannotbe exactly stated for all cases,but the proper regulation of the samewill always be indicated by the appearance of the light, and therequired adj usi ments may be made in accordance with such indications.

Having thus fully described my said invention and the manner ofperforming the same, I wish it understood that 1 do not claim as a.novel feature of my invention a device or apparatus of which the onlypeculiarity is the difference between the dimensions of the twoelectrodes, as I am aware that the employment in anelect riclightapparatus of two electrodes, one of which is larger than the other, hasbeen disclosed in the specification of patents existing long before thedate of my invention. 1. further wish it understood that I do not claimor use any arrangement or combination of parts that will cause theemission of light by the incandescence or heating to whiteness of anelectrode or conductor between two points of contact, except such adegree of incandescence as may be due to the voltaic are. I also wish itunderstood that although the various forms and modifications shown inthe accompanying drawings afl'ord examples in which the said inventionmay be very conveniently and advantageously carried into prac tiee, yetI do not limit myself to the precise details of construction andarrangement of the parts shown, as such details may be further varied ormodified. without changing or departing from the principle of myinvention. Forexample,theupper-electrodemaybeformcd of graphite, copper,or othersuitable metal or material instead of carbon. The constructionof the guides and the means or devices for causing the movement of theupper electrode to efi'ect the variation of the lateral pressure on theother electrode, and the arrangement of the short-circuiting devices aresusceptible of various modifications other than those above described,and, if desired, the lamp may be constructed with the carbon diskorlarge electrodc placed below or in any other convenient position withregard to the other electrode. Furthermore, the variation of the rate ofmovement of the one electrode may be produced by its pressure on theother electrode otherwise than by varying the lateral pressure; but allof these different arrangements or modifications of the said ap iaratusshould embody one of the essential features of myinvention-that is tosay, the compensating action whereby the movement of the one electrodetoward the otheris maintained in due proportion to the combustion of theelectrode; but

I claim 1. In an electric lamp or lightingapparatus in which the lightis produced between two electrodes, substantially as described, thecombination, with the two electrodes, of devices connecting with aswinging or other adjustable holder for one of the electrodes, andarranged to be operated thereby, and to control the movement of thelower elcctrodeby lateral pressure thereon, substantially as described.

2. in an electriclamp or lighting apparatus in which the light isproduced between two electrodes, one of which bears continuously uponthe other,the combination,with the electrode c and mechanism for feedingthe same, of the electrode 1;, arranged to bear'upo'n the lowerelectrode, and connected with devices adapted to automatically controlthe feed of the electrode 0, substantially as described.

In an electric lamp or lighting apparatus in which the light is producedbetween two electrodes, substantially as described, the combination ofthe electrode 0 with the two-part holder 1', and devices connecting witha swingin g holder of the upper electrode, and arranged to be operatedthereby, and to regulate and control the lateral pressure of thetwo-part holder upon the electrode 0, substantially as described.

4. The combination, with the electrodes be, in an electric lamp orlighting apparatus, of the pivoted holder for the electrode 1), the twopart holder *5, through which the lower electrode, c, is fed, anddevices connected with the pivoted holdcrb", and arranged to bearagainst the hinged part of thcholder 'i, substantially as described.

5. The combination,with the two electrodes 1) c, in an electric lamp orlighting apparatus, of a mechanism connected with the pivoted holder ofthe electrode 1), and adapted to act against the hinged or movable partof the twopart holder i, said mechanism being constructed toautomatically establish a short circuit in the apparatus after theelectrode 1) has dropped to a certain extent, substantially asdescribed.

R] .l [ARD \VER] )ERMANN.

\Vitnesses:

LEWIS SAN nisnsox, ROWLAND Gno. Bnowx.

